A new DNA analysis confirms that this ancient skull, found in a Siberian cave, was an early ancestor of man’s best friend. Image via PLOS ONE/Ovodov et. al.

In 1975, a team of Russian archaeologists announced that they’d made a remarkable find: From a cave in the Altai Mountains of Siberia, they’d unearthed a 33,000-year-old fossil skull that resembled a wolf. In 2011, an anatomical analysis suggested that the fossil was a hybrid of a wolf (with its large teeth) and a dog (with its shortened snout), raising the possibility that it was a partly domesticated wolf—in other words, one of the oldest ancestors of the modern dog ever discovered.

At the time, though, DNA analysis was needed to make certain that the fossil came from an ancestor of man’s best friend. A paper published today in the journal PLOS ONE confirms that fact, indicating that the creature was more closely related to modern dogs than wolves, and forcing scientists to reconsider the dog’s evolutionary family tree.

A top view of the skull. Image via PLOS ONE/Ovodov et. al.

A bottom view of the skull. Image via PLOS ONE/Ovodov et. al.

To come to the finding, a team led by Anna Druzhkova of the Russian Academy of Sciences sequenced mitochondrial DNA taken from one of the skull’s teeth. This type of genetic material comes from an organelle inside each cell called the mitochondria, which has a distinct type of DNA that’s separate from the cell’s normal chromosomes. For each individual, mitochondrial DNA is inherited directly from one’s mother without any modifications and thus remains relatively constant over generations, except for the gradual effect of mutations. Similarities found in such DNA collected from various animals helps scientists understand the evolutionary relationships between species.

The research team compared their sample of mitochondrial DNA from the ancient skull with samples from 70 different modern breeds of dog, along with 30 different wolf and 4 different coyote DNA samples. Their analysis found that the fossil’s DNA didn’t match any of the other samples perfectly, but most closely resembled the modern dog breeds, sharing the most similarities with Tibetian Mastiffs, Newfoundlands and Siberian Huskies in particular.

Scientists know that dogs evolved as a result of the domestication of wolves, but the specific time and location of this domestication is still poorly understood—and this discovery further complicates that picture. Most experts agree that dogs predate the invention of agriculture (which happened roughly 10,000 years ago), but some say that domestication may have occurred as long as 100,000 years ago.

This finding—and the previous radiocarbon dating of the skull which established its age—set that event to at least 33,000 years ago. However, dogs may have been domesticated from wolves multiple times, and this breed of Siberian dog may have actually gone extinct, rather than serving as an ancestor for modern dogs. Archaeological evidence indicates that, with the onset of the last glacial maximum (around 26,000 years ago), humans in this area of Siberia may have stopped domesticating dogs, maybe due to food scarcity. In that case, an independent domestication elsewhere may have led to the dogs of today.

On the other hand, domestication in the vicinity of the Altai Mountains, as evidenced by this finding, may have led to the geographic spread of dogs elsewhere in Asia and Europe, even if they died out in Siberia. Previously, many have suggested that the first domestication occurred in the Middle East or East Asia, but this skull could force scientists to rethink their theories. The research team behind the analysis notes that finding more ancient dog remains will help us in putting together the puzzle.

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A new DNA analysis method reveals how ancient skeletons would have looked in the flesh. Image via Jolanta Draus-Barini, Susan Walsh, Ewelina Pospiech, Tomasz Kupiec, Henryk Glab, Wojciech Branicki and Manfred Kayser

For years, when museums, textbooks or other outlets attempted to illustrate what a particular ancient human skeleton would have looked like in the flesh, their method was admittedly unscientific—they basically had to make an educated guess.

Now, though, a group of researchers from Poland and the Netherlands has provided a remarkable new option, described in an article they published in the journal Investigative Genetics on Sunday. By adapting DNA analysis methods originally developed for forensic investigations, they’ve been able to determine the hair and eye color of humans who lived as long as 800 years ago.

The team’s method examines 24 locations in the human genome that vary between individuals and play a role in determining hair and eye color. Although this DNA degrades over time, the system is sensitive enough to generate this information from genetic samples—taken either from teeth or bones—that are several centuries old (although the most degraded samples can provide information for eye color only).

As a proof of concept, the team performed the analysis for a number of people whose eye and hair color we already know. Among others, they tested the DNA of Władysław Sikorski, a former Prime Minister of Poland who died in a 1943 plane crash, and determined that Sikorski had blue eyes and blonde hair, which correctly matches color photographs.

But the more useful application of the new method is providing new information. “This system can be used to solve historical controversies where colour photographs or other records are missing,” co-author Manfred Kayser, of Erasmus University in Rotterdam, said in a statement.

For example, in the paper, the researchers analyzed the hair and eye color for a female skeleton buried in the crypt of a Benedictine Abbey near Kraków, Poland, sometime between the 12th and 14th centuries. The skeleton had been of interest to archaeologists for some time, since male monks were typically the only people buried in the crypt. The team’s analysis showed that she had brown eyes and dark blond or brown hair.

The team is not sure yet just how old a skeleton has to be for its DNA to be degraded beyond use—the woman buried in the crypt was the oldest one tested—so it‘s conceivable that it might even work for individuals who’ve been in the ground for more than a millenium. The researchers suggest this sort of analysis could soon become part of a standard anthropological toolkit for evaluating human remains.

Though submerged in a shipwreck for millennia, the ancient Roman medicinal tablets were kept sealed in tin containers (left), ensuring the pills inside remained dry (right). Image via PNAS/Giachi et. al.

Around 120 B.C.E., the Relitto del Pozzino, a Roman shipping vessel, sank off the coast of Tuscany. More than two millennia later, in the 1980s and 90s, a team sent by the Archeological Superintendency of Tuscany began to excavate the ruins, hauling up planks of rotting wood.

“It wasn’t an easy task. The wreck is covered by marine plants and their roots. This makes it hard to excavate it,” underwater archaeologist Enrico Ciabatti told Discovery News in 2010. “But our efforts paid off, since we discovered a unique, heterogeneous cargo.”

The Relitto del Pozzino shipwreck contained a variety of cargo, including lamps that originated in Asia minor (above). Image courtesy of Enrico Ciabatti

That cargo, it turned out, included ceramic vessels made to carry wine, glass cups from the Palestine area and lamps from Asia minor. But in 2004, the archaeologists discovered it also included something even more interesting: the remains of 2,000-year-old medicine chest.

Although the chest itself—which had presumably belonged to a Roman doctor—was apparently destroyed, researchers found a surgery hook, a mortar, 136 wooden drug vials and several cylindrical tin vessels (called pyxides) all clustered together on the ocean floor. When they x-rayed the pyxides, they saw that one of them had a number of layered objects inside: five circular, relatively flat grey medicinal tablets. Because the vessels had been sealed, the pills had been kept completely dry over the years, providing a tantalizing opportunity for us to find out what exactly the ancient Romans used as medicine.

Now, as revealed today in a paper in the Proceedings of the National Academy of Sciences, a team of Italian chemists has conducted a thorough chemical analysis of the tablets for the first time. Their conclusion? The pills contain a number of zinc compounds, as well as iron oxide, starch, beeswax, pine resin and other plant-derived materials. One of the pills seems to have the impression of a piece of fabric on one side, indicating it may have once been wrapped in fabric in order to prevent crumbling.

Based on their shape and composition, the researchers venture that the tablets may have served as some sort of eye medicine or eyewash. The Latin name for eyewash (collyrium), in fact, comes from the Greek word κoλλυρα, which means “small round loaves.”

Although it remains to be seen just how effective this sort of compound would have been as an actual eye treatment, the rare glimpse into Roman-era medicinal practices is fascinating nonetheless. The vast majority of our knowledge of ancient medicine comes from writings—which may vary in accuracy and lack crucial details—so the presence of actual physical evidence is especially exciting.

A front, profile, and rear view of one of the medicinal tablets. Image via PNAS/Giachi et. al.

New evidence indicates cheese was invented as far back as 5000 BCE, although ancient cheeses wouldn’t have been as varied or refined as the cheeses we have today. Image via Flickr user Skansa Matupplevelser

Archaeologists have long known that cheese is an ancient human invention. Wall murals in Egyptian tombs from 2000 BCE depict cheesemaking, and Sumerian tablets written in cuneiform text seem to describe cheese as well. Our distant ancestors, it seems clear, knew about the wonder that is cheese.

Today, though, cheese lovers have cause to celebrate: New evidence indicates that the invention of the utterly delicious and at times stinky product actually came thousands of years earlier. As described in a paper published today in Nature, chemical analysis of prehistoric pottery unearthed from sites in Poland shows that cheesemaking was invented way farther back than originally believed—roughly 7000 years ago.

A team of researchers from the University of Bristol, Princeton and a group of Polish universities came to the finding by examining an unusual group of artifacts from the Polish sites: clay shards that were pierced with a series of small holes. Struck by their resemblance to in modern-day cheese strainers, they chemically tested the material around the holes, and were vindicated to find ancient traces of the kinds of lipids and fatty acids found in dairy products. These ceramics are attributed to what archaeologists call the Linear Pottery culture, and are dated to 5200 to 4900 BCE.

Researchers tested these perforated ceramic fragments and found ancient dairy residues, indicating they were used as cheese strainers. Image via Salque et. al.

“The presence of milk residues in sieves, which look like modern cheese-strainers, constitutes the earliest direct evidence for cheesemaking,” said lead author Mélanie Salque of the University of Bristol in a statement. “So far, early evidence for cheesemaking were mostly iconographic, that is to say murals showing milk processing, which dates to several millennia later than the cheese strainers.”

Although different cheeses are made by a variety of processes, nearly all start with the separation of milk into liquid whey and solid curds. This is typically accomplished by adding bacteria to the milk, along with rennet (a mix of enzymes produced in animal stomachs), then straining out the liquid from the newly-coagulated curds. These perforated pots, then, seem like they were used to strain out the solids.

The researchers also analyzed other pottery fragments from the site. Several unperforated bowls also had traces of dairy residues, indicating they might have been used to store the curds or whey after separation. They also found remnants of fats from cow carcasses in some of the ceramics, along with beeswax in others, suggesting they were used to cook meat and sealed to store water, respectively. Apart from being capable of making a complex food product like cheese, it seems that these ancient people also created different types of specialized ceramics for different purposes.

The authors of the paper believe this ancient cheesemaking goes a long way in explaining a mystery: why humans bothered to domesticate cows, goats and sheep thousands of years ago, rather than eating their wild ancestors, even though genetic evidence indicates that we hadn’t yet evolved the ability to digest lactose, and thus couldn’t drink milk. Since cheese is so much lower in lactose than milk, they say, figuring out how to make it would have provided a means for unlocking milk’s nutritional content, and gave prehistoric humans incentive to raise these animals over a long period of time, instead of slaughtering them for their meat immediately. Making cheese also gave these people the ability to preserve the nutritional content, since milk spoils much more quickly.

That leaves one more pressing question—what did this ancient cheese actually taste like? Without abundant access to salt or knowledge of the refined heating and ripening processes that are necessary for the variety of cheese we have today, it’s likely that the first cheeses were pretty bland and liquidy. Like ancient Egyptian cheeses, these were probably comparable in texture and taste to cottage cheese, Salque and colleagues noted.

Prehistoric humans correctly depicted the gait of four-legged animals, such as this bull in the famous cave paintings of Lascaux, France, more frequently than modern artists. Image via Horvath et. al., PLOS ONE

The iconic caveman in popular culture is Fred Flintstone: slow-witted and unskilled. In general, we think of the cave art produced by prehistoric people as crude and imprecise too—a mere glimmer of the artistic mastery that would blossom millenia later, during the Renaissance and beyond.

If this is your impression of prehistoric humans, a new study published today in PLOS ONE by researchers from Eotvos University in Budapest, Hungary, might surprise you. In analyzing dozens of examples of cave art from places such as Lascaux, the group, led by Gabor Horvath, determined that prehistoric artists were actually better at accurately depicting the way four-legged animals walk than artists from the 19th and 20th centuries.

The researchers evaluated the prehistoric artists on the basis of the landmark 1880s finding by British photographer Eadweard Muybridge that horses (and, it was later discovered, most four-legged animals) move their legs in a particular sequence as they walk. The “foot-fall formula,” as it’s called, goes LH-LF-RH-RF, where H means ‘hind,’ F means ‘fore,’ and L and R mean ‘left’ and ‘right,’ respectively. At the time of Muybridge, this was thought to be an entirely novel discovery.

Except, as it turns out, prehistoric people apparently knew it too—and got it right in their drawings the majority of the time. Of the 39 ancient cave paintings depicting the motion of four-legged animals that were considered in the study, 21 nailed the sequence correctly, a success rate of 53.8%. Due to the number of combinations of how a four-legged animal’s gait can be depicted, the researchers state that mere chance would lead to a 26.7% rate of getting it right. Cavemen artists knew what they were doing.

This labelled contour drawing of the Lascaux painting shows that the hoofs are placed on the ground in a realistic manner according to the foot-fall formula. Image via Horvath et. al., PLOS ONE

When the researchers looked at 272 paintings and statues of four-legged animals made during modern times but before Muybridge’s findings in the 1880s, such as a famous horse sketch by Leonardo da Vinci, it turned out that these more recent artists were much worse: They only got the sequence right 16.5% of the time. Remarkably, even the 686 paintings and statues studied that were made more recently than 1887, after scientists knew for sure how four-legged animals walked, still got it right just 42.1% of the time.

In this drawing, even Leonardo da Vinci draws the sequence of a horse’s gait in an unrealistic manner. Image via Horvath et. al., PLOS ONE

Even apart from artists, a sizable number of depictions of four-legged animals made during the 20th century specifically for the sake of accuracy got the sequence wrong too, according to references used in the study. Out of 307 renditions analyzed, just 58.9% of depictions in natural history museums were correct, along with 56.9% of those in taxidermy catalogues, 50% of animal toy models and 36.4% of illustrations in animal anatomy textbooks.

Although the amount of art studied in each group varies greatly, the accuracy rate for animal depictions in prehistoric times is noteworthy. How could prehistoric humans possibly be this skilled at depicting animals such as bulls, antelopes and wild horses? For a potential answer, consider the way these ancient artists probably thought about the animals: as prey.

For prehistoric humans, “the observation of animals was not merely a pastime, but a matter of survival,” the study’s authors write. “Compared to artists of latter eras, when people were not as directly connected to nature, the creators of such cave paintings and carvings observed their subjects better and thus they depicted the walk of the animals in a more life-like manner.”

A 24,700-year-old leaf found beneath a Japanese lake, along with other samples, will help scientists more precisely date a range of ancient objects. Image via Richard Staff

Until 1949, when archaeologists dug up prehistoric bones, stone points, charcoal remnants or other artifacts from early human history, they had no way of knowing exactly how old these objects were. Chemist Willard Libby changed that, devising an ingenious method for dating ancient objects based on the types of carbon atoms contained within them.

Libby and his colleagues based their idea on the fact that living things incorporate tiny amounts of a certain isotope of carbon (C-14) from the atmosphere into their structure; when they die, they stop adding new C-14, and the quantity left inside slowly degrades into a different element, nitrogen-14. By figuring out that the half-life of C-14 (the amount of time it takes for half of a given quantity of C-14 to decay into N-14) is 5,730 years, they could chemically analyze the ratio of C-14 to N-14 inside a piece of wood or bone and determine just how long it had been dead.

This technique has revolutionized archaeology, anthropology and other fields, allowing us to determine the absolute age of objects up to around 60,000 years old. All along, though, the precision of this technique has been limited by the fact that the amount of C-14 in the atmosphere has varied over time—and there has never been a great record of just how much it has fluctuated over the years.

With this in mind, a team of scientists from the University of Oxford and elsewhere was particularly excited when they excavated fossilized leaves and cores of sediment layers from beneath Japan’s Lake Suigetsu. These samples might not look like much, but because of the sediment’s unique layering and pristine condition, the find constitutes an unprecedented comprehensive record of atmospheric C-14 from roughly 11,200 to 52,800 years ago. The samples of sediment from this one location on the earth’s surface, in other words, will make our ability to date ancient artifacts found anywhere on the planet significantly more precise.

“The new results offer an important refinement of the atmospheric radiocarbon record and place the radiocarbon timescale on a firmer foundation,” said Jesse Smith, an editor at Science, where the findings were published in a paper today.

A microscopic image of Lake Suigetsu’s sediment layers. Image via Gordon Schlolaut

A specific set of processes and conditions that occur in the lake help to explain why the sediment cores and leaf samples are so valuable. Each winter, small light-colored algae called diatoms die and cover the lake floor; each summer, they are in turn covered by a darker layer of sediment. Because the lake is extremely still, is low in oxygen and has not been disturbed by glaciers or geologic activity anytime in the last 52,800 years, these microscopic layers comprise a complete, annual record preserved in sediment cores.

Moreover, because leaves and other organic materials have been trapped between the layers, the scientists were able to use the amount of C-14 in each leaf to construct a complete picture of atmospheric C-14 over time. Previously atmospheric C-14 records came from marine samples (which differ from those on land) or tree rings (which only dated to a little more than 12,000 years ago), so these cores will greatly improve the precision of radiocarbon dating for older objects. The researchers “anchored” the new C-14 record to previous data by matching up the levels found in the more recent layers of the cores to those already known from the tree rings.

“Although this record will not result in major revisions of dates, for example in archaeology, there will be changes in detail that are of the order of hundreds of years,” said University of Oxford archaeologist Bronk Ramsey, the lead author of the paper. “Such changes can be very significant when you are trying to look at human responses to climate, [which are] often dated by other methods, for example through the Greenland ice cores. A more accurate calibrated time-scale will allow us to answer questions in archaeology, which previously we have not had the resolution to address.”

Researchers suspected that the conditions in Lake Suigetsu could yield such a crucial C-14 record as early as 1993, but they had encountered technical difficulties in extracting and analyzing intact cores until now. “This is a realization of a 20-year-long Japanese dream,” said co-author Takeshi Nakagawa of the University of Newcastle upon Tyne in England. Although it’s taken some time to successfully recover the samples, they will now help researchers to figure out the ages of much older specimens and artifacts.

Bustling Mayan cities such as Tikal, in present-day Guatemala, were likely abandoned due to a combination of deforestation and drought. Photo via Wikimedia Commons/Shark

It’s long been one of ancient history’s most intriguing mysteries: Why did the Maya, a remarkably sophisticated civilization made up of more than 19 million people, suddenly collapse sometime during the 8th or 9th centuries? Although the Mayan people never entirely disappeared—their descendants still live across Central America—dozens of core urban areas in the lowlands of the Yucatan peninsula, such as Tikal, went from bustling cities to abandoned ruins over the course of roughly a hundred years.

Scholars and laypeople have proposed countless theories accounting for the collapse, ranging from the plausible (overhunting, foreign invasion, peasant revolt) to the absurd (alien invasion, supernatural forces). In his 2005 book Collapse, though, Jared Diamond put forth a different sort of theory—that a prolonged drought, exacerbated by ill-advised deforestation, forced Mayan populations to abandon their cities. That hypothesis has finally been put to the test with archaeological evidence and environmental data and the results published this week in a pair of studies.

In the first study, published Tuesday in the Proceedings of the National Academy of Sciences, researchers from Arizona State University analyzed archaeological data from across the Yucatan to reach a better understanding of the environmental conditions when the area was abandoned. Around this time, they found, severe reductions in rainfall were coupled with an rapid rate of deforestation, as the Mayans burned and chopped down more and more forest to clear land for agriculture. Interestingly, they also required massive amounts of wood to fuel the fires that cooked the lime plaster for their elaborate constructions—experts estimate it would have taken 20 trees to produce a single square meter of cityscape.

The central Yucatan lowland, site of most major Mayan cities, was abandoned due to the stresses of deforestation and drought. Image via Barbara Trapido-Lurie/Arizona State University

The other study, published by researchers from Columbia University and elsewhere this week in Geophysical Research Letters, applied quantitative data to these trends. Using population records and measurements from current forested and cleared lands in the region, they constructed a computer model of deforestation in the Yucatan and ran simulations to see how this would have affected rainfall.

Because cleared land absorbs less solar radiation, less water evaporates from its surface, making clouds and rainfall more scarce. As a result, the rapid deforestation exacerbated an already severe drought—in the simulation, deforestation reduced precipitation by five to 15 percent and was responsible for 60 percent of the total drying that occurred over the course of a century as the Mayan civilization collapsed. The lack of forest cover also contributed to erosion and soil depletion.

In a time of unprecedented population density, this combination of factors was likely catastrophic. Crops failed, especially because the droughts occurred disproportionately during the summer growing season. Coincidentally, trade shifted from overland routes, which crossed the heart of the lowland, to sea-based voyages, moving around the perimeter of the peninsula.

Since the traditional elite relied largely upon this trade—along with annual crop surpluses—to build wealth, they were sapped of much of their power. This forced peasants and craftsmen into making a critical choice, perhaps necessary to escape starvation: abandoning the lowlands. The results are the ornate ruins that stretch across the peninsula today.

The collapse is especially intriguing because it seemingly occurred at “a time in which [the Maya had] developed a sophisticated understanding of their environment, built and sustained intensive production and water systems and withstood at least two long-term episodes of aridity,” says B.L. Turner, the lead author of the ASU study. In other words, the Maya were no fools. They knew their environment and how to survive within it—and still they continued deforesting at a rapid pace, until the local environment was unable to sustain their society.

One of the lessons of these complementary studies, says climate modeler Robert Oglesby of the University of Nebraska, who worked on the second paper, is that our reshaping of the environment can often have unintended consequences—and we may not have any idea of what they are until it’s too late. For a present-day example, we can even look to another region where the ancient Maya lived, Guatemala, which is undergoing rapid deforestation. “There’s a tremendous amount of change going on in Guatemala,” said Oglesby. “They may be that much more vulnerable to a severe drought.”

A new technique uses software to detect ancient settlements via satellite imagery

Archaeologists have traditionally found the remains of ancient settlements using a number of labor-intensive techniques: ground surveying, analysis of historic texts, surveys of local residents and the occasional stroke of dumb luck.

These methods have yielded a huge amount of information about ancient human societies, but the process of discovery has occurred in spurts, limited by financial resources and the sheer amount of time researchers had to spend on the ground. Before they could begin digging up a site, it could take months or years to even find one.

A new technique is rapidly turning this paradigm on its head: Instead of getting close to the ground, people are increasingly finding archaeological treasures by looking down from space. And in a new study, Harvard social scientist Jason Ur and MIT research affiliate Bjoern Menze announce the development of a computer program that systematically analyzes satellite images to identify likely locations of ancient artifacts. Their paper, published yesterday in the Proceedings of the National Academy of Sciences, included the analysis of a 23,000-square-kilometer area in Syria and turned up a remarkable 9,000 or so possible settlements.

The potential of this new approach to speed up archaeological discovery is massive. “I could do this on the ground,” says Ur, “but it would probably take me the rest of my life to survey an area this size. With these computer science techniques, however, we can immediately come up with an enormous map which is methodologically very interesting, but which also shows the staggering amount of human occupation over the last 7,000 or 8,000 years.”

The 9,000 possible sites are at least ten times the number of settlements identified previously. The surveyed area is in the northeastern part of Syria, representing part of the Fertile Crescent, home to some of the oldest permanent human settlements in existence, dating as far back as 7,000 B.C.

The analysis program found them by carefully scrutinizing satellite images. Some were detected via radiation from the infrared and near infrared parts of the spectrum, which can show lighter soils with more organic materials, resulting from ancient mud buildings and human settlements turned to dust. Others were identified via artificial mounds, known as Tells, which indicate a series of settlements built atop one another over time.

The researchers then used the volume of settlement sites in a given area as a proxy for continued occupation, and sought to find trends between the placement of settlements and natural resources, such as fresh water. They suggest that complete mapping of sites in the Fertile Crescent will uncover long-term patterns in human settlements during ancient history.

Ur predicts that the new technique will accelerate the pace of archaeological discovery—not just in the Fertile Crescent, but in many other areas around the world.  ”Anyone who comes back to this area for any future survey would already know where to go,” he says. “There’s no need to do this sort of initial reconnaissance to find sites. This allows you to do targeted work, so it maximizes the time we have on the ground.”

The land where the Clovis once hunted. Image courtesy of Wikicommons

In a southwestern corner of what is now Alberta, Canada, camels once roamed. They went extinct at the end the last Ice Age, and their disappearance has generally been attributed to changes in climate and vegetation. But new research suggests that human predators may have contributed to the Western camel’s (Camelops hesternus) demise. A paper in American Antiquity shows that, at a time when ice sheets still covered most of northern Canada, Clovis people on the Western plains were hunting camel for food.

“Our evidence shows that we have to consider that humans may have had some role in their extinction,” said Brian Kooyman, an archeologist at the University of Calgary, and the paper’s lead author.

The study makes the first direct association between Clovis projectile points, stone tools and the remains of a butchered camel. The remains, which radiocarbon dating showed to be about 13,000 years old, were found preserved in windblown sand and silts at Wally’s Beach, an archeological site 108 miles south of Calgary.

“Tracks indicate that [after the horse] they were the second-most common animal at Wally’s Beach and a common part of the fauna,” said Len Hills, a geoscientist at the University of Calgary and collaborator on the study. “Abundant camel tracks at the site clearly show a substantial population.”

Kooyman says this particular camel was likely killed with spears after being ambushed at the top of an embankment leading into a river valley. Hunters may have hidden in nearby shrubs before isolating the animal from the herd.  The hunters then chopped their prey into units of eight vertebrae each, while severing and snapping the camel’s torso into sides of ribs.

But did camels make up a significant part of these people’s diet?

“This is the only site where we have proof of camel use,” said Kooyman. “So far at the site, we have seven killed horses and one camel, so here it is likely they made up about one-eighth of the meat diet.”

At present, there is no evidence that the hunters ever spared the animals in an effort to harness them as pack animals or for human transport, nor that they ever used the camels for anything other than food. But as Kooyman notes, it’s likely these early hunters would have used camel hides for clothing, since life on these post-glacial plains would still have been windy and cold.

Bruce Dorminey is a science journalist and author of Distant Wanderers: The Search for Planets Beyond the Solar System.

A photograph (A) and outline (B) of the human-like drawing. Image from PLoS ONE

For the past 10 years or so, there’s been a surge of interest among archaeologists in the people who discovered the New World. Most of the buzz revolves around when, exactly, those nomads crossed the Bering land bridge into Alaska, with a focus on the distinctive stone tools they used. Nobody talks much about the artistic leanings of the first Americans, simply because examples of their cave paintings, jewelry or other symbolic creations are few and far between.

But in July 2009, after seven years of excavation work, researchers found a humble stick figure engraved in bedrock in Lapa do Santo, in central Brazil. In their report, published yesterday in PLoS ONE, the scientists call it the “oldest, indisputable testimony of rock art in the Americas.”

The figure, 30 centimeters long and 20 centimeters wide, has a “c-like” head, three digits on each hand and an “oversized phallus,” the researchers note. Using radiocarbon dating, the team estimates the engraving, called a petroglyph, is between 9,000 and 12,000 years old.

A few other early American petroglyphs have been reported. In the 1990s, researchers found 11,000-year-old “linear marks” in Epullán Grand Cave, in Patagonia, but whether these were deliberately made by people is debated. More recently, archaeologists discovered engravings of mammoths at sites in Colorado and California, but these rocks could not be precisely dated.

Intriguingly, these early examples of American art are strikingly diverse. For example, the Cueva de las Manos, or “Cave of the Hands,” in Argentina, is about 9,000 years old and full of intricate paintings of hands. And the Epullán Grand Cave contains mostly geometric shapes. The researchers argue that this much artistic range, especially when paired with the noted variability in stone tools, suggests that the first Americans reached the New World much earlier than previously thought.

Australopithecus sediba had a hand built for making stone tools (picture by Peter Schmid; courtesy of Lee Berger and the University of Witwatersrand)

Australopithecines lived in Africa some 4 million to 2 million years ago. Scientists speculate that the australopithecines gave rise to our own genus, Homo, sometime around 2 million years ago, but there’s not much fossil evidence to show exactly when or how this happened. But last year, scientists led by Lee Berger of the University of Witwatersrand announced they had found a possible candidate ancestor of Homo: Australopithecus sediba. The species lived 1.977 million years ago and resembled Homo in many ways.

This week, the researchers published five papers in the journal Science that provide a more in-depth look at the species. Experts are excited about the fossils, but do not agree on where A. sediba belongs in the human family tree—and in some sense, its discovery muddies the picture of human evolution at this critical transition 2 million years ago.

The new studies analyze two partial skeletons found in Malapa Cave in South Africa: a 12- to 13-year-old male and an adult female. Here’s a rundown of the key findings:

Brain: The researchers studied the size and shape of the young male’s brain by taking X-ray scans of his skull and creating a virtual 3-D endocast. A. sediba had a small brain—420 cubic centimeters—only slightly bigger than a chimpanzee brain or half the size of a Homo erectus brain. But the shape and organization of part of the frontal lobe appear similar to Homo. The team says this may mean brain reorganization came before a big jump in brain size in humans.

Pelvis: The pelvis had a mix of australopithecine- and Homo-like traits. This is interesting because some of A. sediba’s more advanced traits, like the shape and orientation of the ilium, were thought to have evolved in the genus Homo to accommodate bigger-brained babies as they came through the birth canal. But since A. sediba had these features and a small brain, another factor probably drove the evolution of these traits; they could be the result of spending even more time walking on the ground and less time in the trees, the researchers suggest.

Hands and Feet: The team found a nearly complete wrist and hand for the species as well as a partial foot and ankle. The foot had a unique mix of traits not seen in any other hominid, suggesting A. sediba had its own form of upright walking and probably still climbed trees. The hand also indicates A. sediba was a climber, but it shows that the hominid had the musculature and anatomy necessary for a “precision grip,” when the thumb meets the fingertips. This movement is what allows you to thread a needle or hold a pencil—and it probably enabled A. sediba to make and use stone tools, the researchers say, although they have not yet found any tools with the species.

Here’s why A. sediba complicates things. For the species to be the ancestor of Homo, it had to have lived before the first species of that genus. That’s just common sense. And it’s true for what the researchers call the “earliest uncontested evidence” of Homo: Homo erectus, at 1.9 million years ago.

But then there’s the contested evidence. At roughly 2.4 million years ago—before A. sediba— a species called H. habilis (“handy man”) lived in Africa, although the researchers say there is disagreement over what fossils should be included in this species. If this handy man is really the earliest member of Homo, it’s hard to call A. sediba an ancestor (unless, perhaps, additional fossil finds push back A. sediba’s age).

In some ways, H. habilis is more human-like than earlier hominids; it had a much larger brain, for example. But in other ways, such as the anatomy of the hand, A. sediba is more human-like than H. habilis, Berger and his colleagues say. What does this all mean? It’s unclear. But at the very least, several different types of Homo-like hominids probably all lived at about the same time—making it a “most challenging endeavor,” the researchers say, to figure out how these forms relate to each other and which if any best represents the ancestor of our genus.

As paleoanthropologists like to say, more fossils may help clarify things—or muddle them even more.

If these bones have been gnawed on, scientists can tell if it was an herbivore or a carnivore doing the chewing (courtesy of flickr user striatic)

When you see news stories with headlines like “Crocodile Ate Our Human Ancestors,” do you ever wonder how the archaeologists knew that the bones had been chewed by a certain creature? This is harder than it seems because carnivores aren’t the only creatures munching on bones, and herbivores are not the strict vegans we think they are. Herbivores eat bones. They’re not delving in to get the yummy marrow, though. Herbivores chew only on dry bones and only when they’re mineral-deprived; the bones provide essential nutrients, phosphorus and a bit of sodium.

This interesting little factoid led a group of archaeologists to conduct a study in a protected bit of Spanish forest so they could learn how to tell apart bones chewed by herbivores and carnivores. (Their results appear in the Journal of Archaeological Science.) They collected 249 bits of bone that had evidence of gnawing, examined them in detail and documented the different types of damage.

Carnivores, the researchers found, chewed on fresh bones that had lots of marrow and lots of meat attached to them. They would sometimes move the bones to a new location and/or pile a bunch together. Their toothmarks consisted of depressions, puncture marks and grooves. And they frequently scooped out the bones.

The damage from herbivores, though, was different. These animals chewed old, dry bones, and their toothmarks, mostly grooves, often appeared on top of signs of weathering. Herbivores preferred flat bones—such as tibias, mandibles and ribs—that they could more easily hold in their mouths. They like to chew on the ends of bones, holding them like a cigar, which can produce an easily recognized forked end.

The researchers carried out their study so that other archaeologists will have a guide for when they encounter gnawed bones. But more important, probably for you, now you know: If you spot a deer in the forest that looks like he’s chewing on the end of a whitish cigar, don’t worry. It hasn’t turned into some rabid were-deer; it just needs a mineral supplement.

Llamas can still be found at Machu Picchu today (image courtesy of flickr user Santiago S.V.)

The Incas dominated much of South America for centuries, building a vast empire that stretched high into the Andes where the terraced city of Machu Picchu still inspires wonder. Now scientists in France and Peru, reporting in the journal Antiquity, reveal what made it all possible: llama dung.

The researchers analyzed mud cores from the bottom of a lake near the Incan town of Ollantaytambo in Peru. These sediment samples contain a record of past environmental conditions in the area. (In some places, scientists have found cores that give records stretching back tens of thousands of years). In the Peruvian sample, the researchers found a sudden increase in maize (corn) pollen starting around 2,700 years ago. Unlike the wild-grown quinoa that the Incas had previously relied upon to survive, cultivated maize provided more energy and could be stored or transported long distances, perfect for fueling a growing empire. But how were they able to grow maize high up in the mountains?

The mud samples also provide that answer. About the same time that there was an increase in maize pollen, there was an increase in oribatid mites, tiny insects that live in soil and feed on feces. The researchers conclude that dung from llamas—which the Incas had domesticated hundreds of years previously—provided food for all those mites. Llamas “defecate communally so [their dung] is easily gathered,” Alex Chepstow-Lusty of the French Institute of Andean Studies explained to the Guardian. The Incans could then use the poop as fertilizer for their maize fields, which reached elevations up to 11,000 feet above sea level. “This widespread shift to agriculture and societal development was only possible with an extra ingredient—organic fertilizers on a vast scale,” Chepstow-Lusty says.

A mummified princess from Thebes (known as Luxor during her time) is the earliest person known to have had coronary heart disease (courtesy of flickr user Rita Willaert)

You might be under the impression that hardening of the arteries, a.k.a. atherosclerosis, is a modern problem. That our diets, rich in animal fats and processed foods, are the problem, and if we only ate like humans used to not so long ago, we’d have no need for bypass surgeries and no one would ever die of a heart attack. But atherosclerosis is common in Egyptian mummies, say scientists who imaged dozens in Egypt, going as far back as 1550 B.C. (Their study, recently published in the journal Cardiovascular Imaging, was presented at the International Conference of Non-Invasive Cardiovascular Imaging earlier this week.)

The researchers created CT scans of 52 ancient Egyptian mummies at the National Museum of Antiquities in Cairo (the mummies couldn’t leave, so the scans were done at the museum). They could see arteries in 44 of the mummies. Of those, 20 had calcification, a marker for atherosclerosis, in their arteries, and in three of the mummies that calcification could be seen in coronary arteries.

Calcification in the right (RCA) and left (LCA) coronary arteries appears white in this CT scan (courtesy of the European Society of Cardiology)

The mummies with signs of atherosclerosis tended to be those that had lived the longest; they averaged 45 years old. One of the three with coronary heart disease was the princess Ahmose-Meryet-Amon, who lived in Thebes around 1580 to 1530 B.C. and died in her 40s; two of her three main coronary arteries were blocked. If she had lived today, “she would have needed bypass surgery,” said one of the study’s co-authors, Gregory Thomas of the University of California, Irvine. She is now known as the earliest person in history to have suffered from coronary heart disease.

At the time when the princess lived, the Egyptian diet consisted of fruit and vegetables, bread, beer and a little domesticated, lean meat, which may sound like a doctor’s recommendation for how to avoid the very problem the princess had. So how did her arteries end up with so much calcification? The researchers have a couple of theories. Parasitic infections were common in ancient Egypt, and the resulting inflammatory response may have predisposed her body to atherosclerosis, much as HIV appears to do so today. Foods during that time were often preserved in salt, which could have had an adverse effect. Or the princess may have eaten a different diet than the average Egyptian; as a royal, she could have feasted on luxury foods like meat, cheese and butter, the very items that heart doctors tell us to avoid.

When Pollard returned to Nantucket, he was given command of another whaling ship, the Two Brothers. And his back luck held. On the night of February 11, 1823, the ship struck a shallow reef off French Frigate Shoals, about 600 miles northwest of Hawaii. The crew members fared better that time, at least, and were rescued the next day by another Nantucket whaling ship. But Pollard’s career as a whaling captain was over. He made one trip on a merchant vessel and then spent the rest of his life as a night watchman, safe on dry ground in Nantucket.

A diver examines an anchor from the Two Brothers (credit: NOAA)

The Two Brothers remained hidden on the bottom of the sea until 2008 when marine scientists went on an expedition to the Northwestern Hawaiian Islands to study the marine life there. This area is part of the Papahānaumokuākea Marine National Monument, 140,000 square miles of protected ocean and one of the world’s largest protected areas.

Divers on the expedition first spotted a large anchor, the first clue that there might be some bigger find on the seafloor. Then they found other items, such as cast-iron pots, called trypots, of the type used to melt whale blubber, indicating that it wasn’t just any old wreck; marine archaeologists concluded that they had found a whaling ship.

Expeditions in 2009 and 2010 turned up items such as ceramics and glass that helped the scientists date the wreck, and first-hand accounts from sailors who had been on the Two Brothers approximately matched the location of the find. Now the scientists are ready to publicly conclude that the wreck was Captain Pollard’s ill-fated ship.

This is the first wrecked Nantucket whaling ship to ever be found, which is rather amazing considering how many hundreds of those ships were in existence during Nantucket’s whaling heyday in the 1700s and early 1800s, and how many must have sunk; whaling was never a safe occupation. “Shipwreck sites like this are important in helping tell the stories of the early days of sailing, including whaling and maritime activities both in the Pacific and around the world,” said Papahānaumokuākea Marine National Monument maritime archaeologist Kelly Gleason, who led the expedition.